Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
16 years ago

baud rate recognizer

hi guys , i need to build a baud rate recognizer as part of a serial communication reciver.

the baud rate recognizer , recives 31h as the first signal and based on it, recognizes the rate.

( 2400, 9600, etc ). does anyone has an idea how should i do it ? cause i'm really clueless ...

3 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    16 years ago

    Hello,

    I would say that you have to generate all the baud rate possible, receive the data and check with the which one you receive well the preamble.

    Jérôme
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    16 years ago

    hi in which application ur using the bit rates depends upon the type of application either in communication wt micro-controller r any other it depends

    as above lets mentioned u need to generate the baud clks wt respect to ur reference clk
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    16 years ago

    If you only need to support a relatively small number of baud rates, you could synthesize several UARTs in parallel, one for each baud rate. Then, you just wait for one of the UARTs to correctly receive the 31h.

    A more traditional approach would be to measure the time between transitions when receiving the 31h. For example, you could measure the time of the start bit. From this, you can calculate the baud rate.